Phần típ theo nè!
Câu 5: Tìm \(x\):
Đề bài : \(xxx\) - \(x
\) x 105 = 30
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Câu 6: Tìm \(x \):
a) \(x \) x 7 + \(x\) = 384.
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b) \( x\)\(x
\) - \(x\) x 2 = 378.
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Câu 7: Tìm số tự nhiên ab biết ab x 9 = 2ab :
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Câu 8: Viết biểu thức sau thành tích 2 thừa số:
Đề bài: ab + ab x 2 + ab x 4 + ab =
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-------- Còn nữa -------
\(\left(\sqrt{9}+\sqrt{4}\right)\sqrt{x}=10\)
\(\Rightarrow\left(3+2\right)\sqrt{x}=10\)
\(\Rightarrow5\cdot\sqrt{x}=10\) \(\Rightarrow\sqrt{x}=2\)
=> x = 4
Ta có: 2a = 2b = 2c => a = b = c
\(\Rightarrow A=\frac{a-b+c}{a+2b-c}=\frac{a-a+a}{a+2a-a}=\frac{a}{3a-a}=\frac{a}{2a}=\frac{1}{2}\)
1. \(\left(\sqrt{9}+\sqrt{4}\right)\sqrt{x}=10\)
\(\Rightarrow\left(3+2\right)\sqrt{x}=10\)
\(\Rightarrow5\sqrt{x}=10\)
\(\Rightarrow\sqrt{x}=2\)
\(\Rightarrow\left(\sqrt{x}\right)^2=2^2\)
\(\Rightarrow x=4\)
2. \(2a=2b=2c\)\(\Rightarrow a=b=c\)\(\Rightarrow A=\frac{a-b+c}{a+2b-c}=\frac{a-a+a}{a+2a-a}=\frac{a}{2a}=\frac{1}{2}\)